1. Field of the Invention
This invention relates generally to telecommunications, and, more particularly, to wireless communications.
2. Description of the Related Art
Cellular communication systems have increasingly become popular over the last several years. Some well-known cellular technologies include Advance Mobile Phone Service (AMPS), Global System for Mobile (GSM), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiple Access (OFDMA). Like the cellular communication systems, wireless local area networks (WLANs) have also gained popularity over the years. Some WLAN standards that have become popular include the 802.11x standards that have been ratified by the Institute of Electrical and Electronics Engineering (IEEE). Exemplary IEEE 802.11x standards include 802.11, 802.11a, 802.11b (also known as Wi-Fi), and 802.11g.
In view of the widespread use of cellular communications and WLAN communications, there has been a recent trend to develop integrated mobile terminals that allow coexistence between cellular and WLAN modes of operation. An integrated mobile terminal can thus communicate with both the existing cellular network infrastructure (for voice and/or data), and WLAN networks for high-speed data applications. While an integrated mobile terminal may be used to access both the cellular network and the WLAN network, these two networks largely remain independent, and thus are typically accessed independently of one another.
Advantages in converging cellular and WLAN technologies into a common mobile terminal may exist. However, these integration aspirations have given rise to security issues, such as determining an efficient and secure manner of authenticating a mobile terminal within two different networks (e.g., the cellular network and the WLAN network). Currently, a WLAN subscriber using an integrated mobile terminal has to be authenticated both for cellular access and WLAN access.
Existing procedures for authenticating the mobile terminal for both cellular and WLAN access, however, may be inefficient because the mobile terminal is authenticated with each of the supported networks (e.g., cellular and WLAN) using separate, independent authenticating keys. That is, the user has to be authenticated to the cellular network using a first key, and has to be authenticated to the WLAN network using a different, independent key. Managing the distribution of different authentication keys for the different networks can give rise to administrative challenges for the service provider or network manager. This administrative problem may be further exacerbated as the mobile terminals are designed to support communications with more than two networks.
The present invention is directed to addressing one or more of the problems set forth above.